Closing mechanism for a harvester safety door

ABSTRACT

A pivoted safety door for a harvester is disposed ahead of the concave and has a separately pivoted lip which normally rests on a front edge of the concave. An adjustably biased detent mechanism releases the lip, permitting it to pivot out of engagement with the concave, when a rock or the like of substantial size attempts to enter the threshing chamber and is engaged by the threshing rotor. A first manual control is provided for pivoting the main body of the door from its tripped position to a closed position. A second manual control is provided for pivoting the lip relative to the door to restore it to its detented position, this last mentioned function being effected after the main body of the door has been restored to a closed position. The detent mechanism for the lip includes a pair of adjustably loaded spring biased plungers which act on opposite sides of a detented part. The laterally opposite ends of the safety door are sealed in relation to vertical walls of the harvester by a pair of special seal structures which are pivoted to the harvester coaxially with the main body of the safety door. The seal structures each include a rigid longitudinal sealing member in overlapping relation to one end of main body of the safety door with a free end loosely connecting with the leading edge of the concave and includes a flexible sealing element in engagement with the adjacent vertical wall. The rear ends of the seal structures and safety door rest on and move up and down with the front of the concave when the latter is adjusted to change the clearance between the concave and the threshing rotor. The seal structures also serve as stops to limit upward swinging movement of the safety door at the time it is closed to its operating position.

TECHNICAL FIELD

This invention relates to a harvester or combine of the type having athreshing rotor and a cooperating concave for effecting threshing ofagricultural crops. More particularly, the invention relates to a safetydoor for preventing rocks or the like from entering into the spacebetween the threshing rotor and the cooperating concave.

BACKGROUND OF THE INVENTION

The threshing mechanism of a harvester typically includes a threshingrotor and an underlying concave which cooperate to thresh the grain orseeds from the crop passing between the rotor and the concave. The cropis delivered to the threshing mechanism by a feeder receiving the cutcrop from the header located forwardly of the harvester. Occasionally,when the combine or the harvester is operating in rocky regions, theheader will pick up a rock along with the crop, and unless the rock isremoved before it enters between the threshing rotor and the cooperatingconcave, extensive damage may be caused to the threshing mechanism.

It is well known to provide a safety door or rock trap to interceptrocks or the like before they pass to the space between the threshingrotor and the concave. One such safety door is shown in U.S. Pat. No.4,195,644. In the before mentioned patent there is illustrated a safetydoor which is hinged at its forward end and includes a pivotabledetented lip, the rear edge of which rests on a forward edge of theconcave. The present invention is directed to substantially improve thefunction and operation of a safety door of the type shown in thebefore-mentioned U.S. Pat. No. 4,195,644.

BRIEF DESCRIPTION OF THE INVENTION

The invention, which is particularly useful in a harvester having athreshing chamber with a crop inlet, a rotatable threshing rotor withinthe threshing chamber and a concave beneath the rotor may becharacterized by a safety door constituting a portion of a floor of theinlet to the threshing chamber forward of the concave including a mainbody portion pivotally connected at its front end to the harvester on afirst horizontal axis generally parallel to the axis of said threshingrotor together with a lip portion pivotally connected to the rear of themain body portion for pivotal movement about a second horizontal axisgenerally parallel to the first horizontal axis between a detentedoperating position in which an edge of the lip portion is in overlappingengagement with the front end of the concave and a tripped position inwhich the lip portion is disengaged from said concave.

The invention is further characterized by a detent mechanism carried bythe safety door for normally maintaining the lip portion rigid withrespect to said main body portion and a pair of manually operatedcontrols for the lip and main body portions of the safety door. Themanually operated control for the lip portion is operable to pivot thelip portion from its tripped position to its detented operating positionand includes a transversely extending part the end of which presents awrench receiving head.

The manually operated control for the main body portion includes awrench receiving part nonrotatably secured to the main body portion incoaxial relation to the first horizontal axis.

The transversely extending part of the manually operated control for thelip portion may be spaced downwardly from the second horizontal axis soas to avoid interference with other structural parts of the combine.

BRIEF DESCRIPTION OF THE DRAWINGS

One embodiment of the invention is illustrated in the drawings in which:

FIG. 1 is a partial side view of a combine harvester with portionsbroken away for illustration purposes;

FIG. 2 is a view taken along the line II--II in FIG. 1;

FIGS. 3A and 3B are views taken along the line III--III in FIG. 1;

FIG. 4 is a view taken along the line IV--IV in FIG. 1;

FIG. 5 is a longitudinal vertical section through the safety doorshowing the lip portion in a tripped position; and

FIG. 6 is a view taken along the line VI--VI in FIG. 4 showing both thelip portion and safety door and tripped and rock discharging positions.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring to FIGS. 1 and 2 the combine 11 includes the threshing rotor12 rotatably mounted on a transverse horizontal axis 13 within asurrounding threshing chamber in the form of a foraminous cage 14 whichincludes a concave 16 at its bottom in underlying relation to thethreshing rotor 12. The rear end of the concave 16 is supported on themain part 17 of the cage 14 by adjustable pivots 18, 18'. The threshingclearance F between rasp bars 21 at the outer periphery of rotor 12 andthe concave 16 can be adjusted by interconnected eccentric mechanisms23, 23', which upon being rotated effect vertical adjustment of theconcave 16.

Referring also to FIGS. 3A and 3B, a safety door 26 embodying thepresent invention is disposed in front of the concave 16 at the point ofentrance of the crop material through a crop inlet 19 in the cage 14.The safety door 26 is pivotally mounted on a pair of vertical sidewalls27, 28 of the inlet 19 by a shaft 29. Referring also to FIGS. 4 and 5the safety door 26 constitutes a portion of the floor in the inlet 19 tothe threshing chamber or cage 14. The door 26 includes a main bodyportion 31 having a curved top plate 32 secured as by welding to ahollow cylindrical part 36 of the shaft 29. One end of the hollowcylindrical part 36 is in cooperative pivotal engagement with astationary cylindrical bearing pin 37 welded to a plate 38 which in turnis rigidly secured to the wall 28 by cap screws 39. At the other end ofthe door 26, cylindrical rod part 41 is nonrotatably secured to thecylindrical shaft part 36 by a pin 42 and is pivotally mounted in abearing bracket 43 secured to the sidewall 27 by cap screws 44. Theoutboard end of the rod part 41 is hex shaped to constitute a wrenchreceiving head 46.

The safety door 26 includes a lip portion 51 pivotally connected to astationary shaft part 52 on the rear end of the main body portion 31 ona transverse, horizontal pivot axis 53 which is parallel to the pivotaxis 54 of shaft 29 and to the axis 13 of rotor 12. The shaft part 52 issecured by welding to vertically extending, fore and aft reinforcingribs 56, 57, 58, 59 welded to the underside of the plate 32 of the mainbody portion 31. The lip portion 51 includes an angle shaped part 61 anda U-shaped channel part 62, whose flange ends are welded to a flange 63of the angle shaped part 61, in surrounding pivotable relation to theshaft part 52. The flange 64 of the angle shaped part 61 constitutes alip which normally extends rearwardly in overlapping engagement with thetop front edge 66 of the concave. The lip portion 51 includes a cammingpart in the form of a knife like detented element 71 secured by weldingto a reinforcing plate 72 complementary to and welded to the flange 63of angle shaped part 61. In the detented operating position of the lipportion 51 shown in FIGS. 1, 2 and 3, and detented element 71 isreleasably engaged by opposed plungers 76, 77 whose inboard ends presentconvex camming surfaces 78, 79 in engagement with concave cammingsurfaces 81, 82 on transversely opposite sides of the detented element71. The knife edges 83, 84 on the detented element 71 serve also ascamming surfaces during relatching of the lip portion 51 in its detentedoperating position. The lip portion 51 also includes a manually operatedmechanism by which it may be relatched which includes a transverse rod86 extending through aligned openings in vertical brackets 87, 88, 89 towhich it is welded. The brackets 87, 88, 89 are in turn welded to thetransverse plate 72. The outboard end of the rod 86 is hex shaped toform a wrench receiving head 91.

The detent mechanism also includes plunger assembly 92 having a mountingbracket 93 with a horizontal part 94 releasably secured to the plate 32of the main body portion 31 by releasable fastening means in the form ofscrews 96 and nuts 97. The mounting bracket 93 includes a pair ofparallel, transversely spaced, downwardly extending walls 101, 102 whichextend in a fore and aft direction and present aligned openings 103, 104through which the plungers 76, 77 and their biasing springs 106, 107freely extend. The plungers 76, 77 are reciprocably mounted in guideblocks 110, 110' welded to the horizontal part 94 of the bracket 93 andhave washers 111, 112 welded thereto to provide shoulders on theplungers in axial thrust transmitting engagement with coil springs 106,107. The outboard ends of the plungers 76, 77 pass through openings 113,114 in backup plates 116, 117 which are adjustable secured to the walls101, 102 of the bracket 93 by releasable fastening means in the form ofscrews 121 and nuts 122. The screws 121 extend through bushings 123 andwashers 124 and by adding or substracting washers between the bushings123 and the backup plates 116, 117 the bias or thrust of the springsagainst the plungers 76, 77 can be increased or decreased.

By making the plunger assembly 72 in the form of a replaceable unit, itcan be replaced as a unit in event of field failure, and it can bemanufactured as a separate assembly thereby permitting better control oftolerances. Also it will be noted that the holes 126 in the bracketthrough which the screws 96 extend are considerably larger in diameterthan the diameter of the screws 96, thereby permitting the horizontalposition of the bracket 93 to be shifted to accurately position theplungers 76, 77 relative to the detent element 71 on the lip portion 51.

When a rock is conveyed via feeder floor 130 onto the door 26 and isengaged by a rasp bar 21, the force exerted against the body portion 31of the door will be sufficient to trip the lip portion 51. That is, thedetented element 71 will swing downwardly out of detented engagementwith the inboard ends of the plungers 76, 77 as the flange or lip 64 ofthe lip portion 51 swings upwardly and forwardly out of engagement withthe front end of the concave 16. The fully tripped condition of the lipportion 51 is shown in FIGS. 5 and 6. FIG. 6 not only shows the lipportion 51 in its tripped position, but also shows the main body portion31 of the safety door 26 in its tripped position in which the rock whichcaused the door to open would be discharged from the threshing area ofthe harvester or combine.

In using the safety door mechanism of U.S. Pat. No. 4,195,644 it wasfound that an excessive amount of effort was required to close thesafety door and relatch the pivotable lip portion thereof. In the hereinillustrated safety door, separate manually operated mechanisms areprovided for relatching the lip portion 51 and for reclosing the safetydoor 26. In reclosing the safety door 26, the door is first swung orpivoted from its tripped or open position shown in FIG. 6 by engagingthe head 46 of shaft 29 with an appropriate wrench and then exertingmanually generated torque to the shaft in the appropriate direction.This effort will swing the door 26 upwardly and rearwardly to theposition shown in FIG. 5. The seal structures 131, 132, hereinafterdescribed, serve as a stop to limit upward swinging (closing) movementof the door 26. The combine operator next fits an appropriate wrench onthe head 91 of the rod 86 on the lip portion 51 and turns the head 91 ina counterclockwise direction, as shown in FIG. 5, until the concavecamming surfaces 81, 82 of the detented element 71 are engaged by thecamming surfaces 78, 79 on the heads or ends of the plungers 76, 77. Itwill be noted that the head 91 of the manually operated mechanism forrestoring the lip portion 51 to its detented operating position isoffset or spaced downwardly from the axis 53 of the lip portion. Thisoffset condition avoids interference with structural members of theharvester and also avoids interference with a seal structure which willnext be described.

In using prior art safety door constructions, grain loss occurred, insome combines, between the lateral ends of the safety door and theadjacent sidewalls of the inlet to the threshing chamber or cage. Inorder to reduce such loss, seal structures 131, 132 are provided betweentransversely opposite ends of the safety door 26 and the side walls 27,28. The seal structures 131, 132 are substantially reverse images of oneanother and, therefore, only seal structure 131 will be described indetail. Referring particularly to FIGS. 4 and 6, the seal structure 131includes a fore and aft extending part 136 having an inboard portion 137in overlapping complementary relation to the upper surface 138 of thelateral end of the top plate 32 of the main body portion 31 of the door26. The seal structure 131 also includes a fore and aft extendingportion in the form of a flexible sealing part 139 which issubstantially coextensive with the adjacent end of the safety door 26and in sealing engagement with the sidewall 27. The sealing part 139 issecured to a vertical fore and aft extending flange 141 depending fromthe transversely extending part 136, to which it is welded, by a clip142 held in place by a pair of rivets 143. The rear end 146 of theflange 141 extends beneath the front edge 66 of the concave 16 and therear end 147 of the top part 136 extends rearwardly in overlappingrelation to the edge 66. Thus, the ends 146, 147 form a motiontransmitting connection between the concave 16 and the seal structure131. The seal structure 131 is pivotally connected to the rod part 41 ofthe shaft 29 by a bushing 148 which is welded to part 141 of the sealstructure 131. The bushing 148 pivotally engages rod part 41 for pivotalmovement independently of door 26 but on the same axis 54. When theconcave is vertically adjusted by eccentive mechanisms 23, 23',interconnected by the hex shaft 25, the seal structure and door 26 willmove vertically with the edge 66 of concave 16. When the door 26 tripsthe seal structure 13' remains in place, as is illustrated in FIG. 6.When the door is relatched, the seal structure 131 serves as a stop orabutment limiting upward swinging movement of the door 26 as it swingsto its closed position.

The safety door mechanism herein disclosed has an improved sealingrelationship with the sidewalls of the crop inlet to the threshingchamber, is easier to relatch from a tripped position by virtue of twoseparate manually operated mechanisms for the lip portion and the doormain body and the improved detent mechanism provides superiorperformance because of its adjustably positioned plunger assembly andadjustably biased plungers.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:
 1. A harvester having athreshing chamber, a crop inlet to the threshing chamber, a rotatablethreshing rotor within the threshing chamber and a concave beneath therotor having a predetermined threshing clearance with the latter,characterized bya safety door constituting a portion of a floor of theinlet to the threshing chamber forward of said concave, said safety doorincludinga main body portion pivotally connected at its front end to theharvester on a first horizontal axis generally parallel to the axis ofsaid threshing rotor and a lip portion pivotally connected to the rearof the main body portion for pivotal movement about a second horizontalaxis generally parallel to said first horizontal axis between a detentedoperating position in which an edge of said lip is in overlappingengagement with the front end of said concave and a tripped position inwhich said lip is disengaged from said concave, a detent mechanismcarried by said safety door for normally maintaining said lip portionrigid with respect to said body portion a manually operated control forsaid lip portion operable to pivot said lip portion from its trippedposition to its detented operating position including a transverselyextending part the end of which presents a wrench receiving head, and amanually operated control for said main body portion including a wrenchreceiving part nonrotatably secured to said main body portion in coaxialrelation to said first horizontal axis.
 2. The combination of claim 1wherein said transversely extending part is spaced downwardly from saidsecond horizontal axis.